Tool



D April 28, 1942. E. l.. JOHNSON TOOL Filed June 3, 1940 2 Sheets-Sheet 2 HTraE/VEKS.

Patented Apr. 23, i942 UNTE STATES @FHQE 4: Claims.

The present invention relates generally to turning tools, and more particularly to a portable lathe for dressing down armature commutators and for other such work requiring eXactness.

There are, of course, on the market both powerdriven and manually operable lathes of various kinds. However, heretofore there has never been developed a small compact portable lathe which is particularly adapted to true the armature commutators of car generators, starters, and the like, and to perform similar tasks.

Therefore, an object of the present invention is to provide a small portable lathe which is particularly adapted to true the armature commutators of automobile generators, starters, or the f like, and to perform similar services.

Another object is to provide a portable lathe adapted to turn down the armature commutator of a generator, or the like, in which the armature is simultaneously rotated and moved longitudinally through the medium of microscopic threads.

Another object is to provide a portable lathe adapted to true the armature commutator of a generator, or the he, which is constructed to include a device for cleaning mica and for easily removing the armature after the truing operation.

Another object is to provide a portable lathe which is small and compact, which is sturdy in construction, and which is adapted to fulfill `all of the objects and advantages sought therefor.

Other objects and advantages will be apparent from the following description, taken in conjunction with the accompanying drawings, in which:

Fig. 1 is a top plan View of a preferred embodiment of the present lathe;

Fig. 2 is an end elevation View of the lathe shown in Fig. l;

Fig. 3 is a front elevation View of the lathe shown in Fig. 1;

Fig. 4 is a section on the line ffl-i of Fig. l;

Fig. 5 is a section on the line 5-5 of Fig. 1;

Fig. 6 is a top plan View on a reduced scale of the lathe shown in Fig. l with an armature dotted in operative relation. thereto for turning down, parts of the lathe being broken away to conserve space; and,

Fig. 7 is a fragmentary end View on a reduced scale of the lathe shown in Fig. l with an armature dotted in in operative relation thereto for cleaning the mica.

Referring to the drawings more particularly by reference numerals, Ill indicates generally .a lathe constructed in accordance with the teachings of the present invention. The lathe I includes .a casting I I which comprises a base block I2 adapted to be received by a vise, or the like; a split `cylindrical body I3 connected to the upper part of the base block I2; spaced ears I4 extending from the cylindrical body I3; and an extension I disposed at one side of the base block I2.

A spindle or cylinder I'I having microscopic threads It throughout its length is disposed Within the split cylindrical body I3. A plug I9 having a threaded yaperture closes one end of the cylinder I'l and threadedly receives a threaded shaft EI. The shaft 2I terminates at the interiorly disposed end in areduced portion 22 (Fig. 4). An annular member 23 is disposed about the reduced portion 22 and against the shoulder formed in the offset of the reduced portion 22 from the main body of the shaft 2 I. The exteriorly disposed end of the shaft 2l is unthreaded in a portion 25, through which extends -a member 26 that serves as a handle for movement of the shaft 2l into and out of the cylinder Il. An arm 2 threadedly engages the shaft 2l between the unthreaded portion and the cylinder II. The arm 2l terminates in a handle 28. A removable split tapered chuck or sleeve 29 is shown disposed in that end of the cylinder I'I remote from the plug I9. A J-holt 3B extends through the base 4block I2. The shorter leg of the J -bolt 3i! engages an opening in the cylindrical body I3. A wing nut 3l is threaded on the extremity of the longer leg of the bolt 30 for purposes of `applying closing pressure to the cylindrical body I3.

A threaded post 32 (Fig. 2) is secured into and extends rearwardly from the extension I5. A member 33 is disposed about the post 32 by an aperture adjacent one end and has secured to its other end a steel blade 3f! which is disposed in substantially parallel relation with the post '32. The steel blade 35 rests in part in a right angle groove (Fig. 3) formed in one corner of the extension Iii. A plate 35 secured to the top of the extension I5 by a wing nut 3l threaded on a threaded post 3% maintains the steel blade 34 in predetermined position. The steel blade 34% terminates in a sharp cutting point 39. A dial member 40 is threaded on the post 32 and is employed to determine the position of the steel blade 34. The plate 36, in extending over a portion of the steel blade 3i, serves also as a guard for the point 39.

A mica remover I3 includes a shaft M supported in the ears I4 for longitudinal and rotary movement. A post 45 is connected to that end of the shaft 44 which extends exteriorly of the ears I4 in the vicinity of the extension I5. A serrated blade 46 is secured to the post 45 transversely thereof by a threaded bolt 41, which extends through the serrated blade 45 and into a threaded aperture in the post 45. Washers 48 are disposed on each side of the blade 46. A handle 56 is secured by a threaded bolt 5| to the shaft 44 between the ears I4. A stop and guide member 52 is likewise secured to the shaft 44 by the bolt 5|. The member 52 is located relative to the lblade 46 to stop the pivotal movement of the latter short of the threads I8 of the cylinder I1 to prevent accidental injury of the threads IB.

Operation The casting II serves as the foundation with which the remaining elements are operatively associated. After the shaft 2|, with its threadedly engaged arm 21 and handle member 26, has been threaded into the cylinder I1 by means of the plug I9, the cylinder I1 is disposed within the split cylindrical body I3, the interior of which is cast smooth. By means of the wing nut 3| and the J-bolt 36, the split cylindrical body I3 is closed into firm relationship with the cylinder I1, which has the continuous microscopic thread I8 extending along the full length thereof. The arm 21 with its handle 28 is then employed to rotate the cylinder I1 to cut a corresponding microscopic thread into the erstwhile smooth inner surface of the cylindrical body I3. Meanwhile, the mica remover 43 and the steel blade 34 and its associated elements are connected to the casting II in a manner obvious from the foregoing description. The lathe I is then ready for use.

The split tapered sleeve 29 is disposed about the shaft of an armature 55 adjacent the commutator 5G thereof. The sleeve-encased shaft end is then forced into that end of the cylinder I1 remote from the plug I9 until there is established a rm relationship. This disposes the commutator 56 in a position to be turned down by the blade 34. The blade 34 is adjusted to cutting position by means of the dial 40.

After the blade 34 has been properly adjusted, the cylinder I1 is rotated by means of the arm 21 and handle 28 until the complete surface of the commutator 56 has been cut by the blade 34. In the rotation of the cylinder I1, the full surface of the commutator 56 is exposed to the relatively sharp point 35 of the blade 34, due to the microscopic threads on the cylinder I1.

After the surface of the commutator 56 has been cut by the blade 34, the mica remover 43 is brought into action. The serrated blade 46 is disposed in one of the crevices separating the copper sections of the commutator 56. The edge is then moved rapidly longitudinally of the commutator 56 by means of the handle 56 to free undesirable material lodged therewithin. This action is repeated for each of the openings, The stop member 52 prevents the blade 46 from being inadvertently drawn across the fine threads I8 of the cylinder I1.

After the foregoing, the shaft 2| is actuated by means of the handle member 26 to remove the armature from the lathe I6, the shaft 2| thus serving as a plunger. The annular member 23 serves to eject the sleeve 29 where this action is necessary.

The arm 21 is not fixed to the cylinder I1, although this construction may be employed if desired. It is not necessary to rotate the cylinder I1 for movement to the right (Fig. 4) inasmuch as the wing nut 3| (Fig. 2) may be loosened and the cylinder I1 subsequently bodily moved to the right.

The several elements of the present construction are, of course, to be constructed of suitable material and of proper configuration. It is contemplated that the configurations of the several elements may be changed within the scope of the present invention.

It is manifest that there has been described and shown a construction which fulfills all of the objects and advantages of the present invention. It is to be understood that the foregoing description and accompanying drawings have been given by way of illustration and example, and not for purposes of limitation, the invention being limited only by the claims which follow.

What is claimed is:

l. A lathe comprising a casting including a base and a split cylindrical body portion, a threaded cylinder disposed within the cylindrical portion, means releasably closing the split cylindrical body into engagement with the cylinder, means for rotating the cylinder to effect longitudinal movement thereof through the cylindrical body, means for maintaining a commutator in engagement with the cylinder for rotation therewith, and adjustable stationary means disposed to turn down the commutator during the rotation of the cylinder.

2. A lathe comprising a support, a split sleeve connected to the support, means for supporting a commutator disposed in said sleeve for rotary movement, means for rotating said last means, means for turning down the commutator as the first means is rotated, and means for ejecting the commutator from engagement with the first means.

3. A tool for turning down the commutator of an armature comprising a base including a split sleeve, a microscopically threaded cylinder releasably secured within the sleeve for rotative and longitudinal movement therein, means for rotating the cylinder, means for securing a commutator to one end of the cylinder for movement therewith, and an adjustable stationary cutter secured to the base in a position to be adjusted into cutting engagement with the commutator, whereby rotation of the cylinder effects a turning down of the commutator.

4. A tool for turning down the commutator of an armature comprising a base including a split sleeve, a microscopically threaded cylinder releasably secured within the sleeve for rotative and longitudinal movement therein, means for rotating the cylinder, means for securing a commutator to one end of the cylinder for movement therewith, an adjustable stationary cutter secured to the base in a position to ybe adjusted into cutting engagement with the commutator, and means for forcibly and positively removing the commutator from engagement with the cylinder.

ERNEST L. JOHNSON. 

